Medical News Today -- DNA testing for gene variants that can increase the risk of major coronary events in certain patients taking the anti-clotting drug Plavix® (clopidogrel bisulfate) is now being performed by Quest Diagnostics (NYSE: DGX) for Scripps Health patients electing to undergo coronary stent procedures. Scripps Health is believed to be the first health system in the U.S. to deploy this genetic testing service for coronary stent patients as part of patient treatment. Scripps physicians will initially offer the genetic tests to elective stent patients before they undergo their procedures at Scripps Green Hospital in San Diego.